1. Field of the Invention
Exemplary embodiments disclosed herein relate to improved methods for activating the cure of certain chain growth and cross-linkable polymerizable compositions of monomers, oligomers, and/or polymers through introduction of an activating agent, and to the use and/or application of such as commercial products and compositions, including, for example, monomer-based products (e.g., inks, adhesives, coatings, sealants or reactive molding) and polymer-based products (e.g., fibers, films, sheets, medical polymers, composite polymers and surfactants).
2. Background
Methylene malonates are compounds having the general formula (I):

wherein R and R′ may be the same or different and may represent nearly any substituent or side-chain. Such compounds have been known since 1886 where the formation of diethyl methylene malonate was first demonstrated by W. H. Perkin, Jr. (Perkin, Ber. 19, to 1053 (1886)).
However, earlier methods for producing methylene malonates suffer significant deficiencies that preclude their use in obtaining commercially viable monomers. Such deficiencies include unwanted polymerization of the monomers during synthesis, formation of undesirable side products, degradation of the product, insufficient and/or low yields, and ineffective and/or poorly functioning monomer product. These problems have impinged on their practical use in the production of commercial and industrial products.
Certain co-inventors of the instant application have recently filed patent applications on improved methods of synthesis of methylene malonates, namely, PCT/US11/056903 Synthesis of Methylene Malonates Substantially Free of Impurities, and PCT/US11/056926 Synthesis of Methylene Malonates Using Rapid Recovery in the Presence of a Heat Transfer Agent. The synthesis procedures provided therein result in improved yields of heretofore elusive high quality methylene malonates and other polymerizable compositions.
With the advent of improved synthesis processes for disubstituted vinyl monomers such as methylene malonates, there exists a need in the art for suitable methods of activating polymerization in order to provide the desired outcomes, including new classes of commercially viable products.
The polymerizable compositions are amenable to chain-building and/or cross-linking polymerization by anionic or free radical initiation and have the potential to form the basis of a highly valuable and large-scale platform for the chemical synthesis and formulation of new chemical products, including inks, adhesives, coatings, sealants, moldings, fibers, films, sheets, medical polymers, composites, surfactants and the like.
For example, in the area of addition polymerization, primarily with acrylates and methacrylates, the historic systems for activation have involved relatively high levels of catalyst, typically 2% by weight or more for most catalysts, accelerator and/or activator components. As such, significant mixing events, often coupled with substrate priming, were required to facilitate an appropriate polymerization (i.e., speed, degree of polymerization, etc.). Such requirements could be found, for example, in systems used in bonding inactive surfaces. Therefore, there is a need in the art for more facile polymerization initiation and management tools. Such improvements are not readily apparent given the state of the prior art.
As known in the art, materials such as cyanoacrylates may not require such high levels of catalysts, accelerators or activators. However, because such systems exhibit poor properties, there has not been an impetus in the art to develop improved methods of activation, particularly on inactive substrates, beyond the inclusion of additives such as calixerenes, crown ethers and the like to facilitate the strengthening or creation of anionic initiators on inactive substrate surfaces. Indeed, primers are often used to improve performance. It has been found that substantially perfect stoichiometric mixing is required with these systems to initiate polymerization, especially for spanning large distances from the initiation event (e.g., primed surface), large gap filling of 10 mils or more, potting applications, or molded parts. Again, improvement in performance is desired in the art with regard to ranges of physical and chemical properties.
Given the state of the art, new solutions not immediately apparent are required to to provide the desired outcomes, especially for consistently reactive formulations with long term shelf life at ambient temperatures. Further, there is a need in the art to provide a polymerization system including an addition polymerizable composition and a suitable initiation component or components provided at low levels and without the need for perfect or stoichiometric mixing.
Further, there is a need in the art for polymerizable systems that provide consistent reactivity, that are storable under ambient conditions, and that are substantially free of impurities that affect reactivity and shelf life.
As already noted, a consistently reactive, ambiently storable set of reactive formulations is important to these aforementioned products, their use and incorporation into resultant articles. Accordingly, those products must be substantially free of any impurities that may interfere with consistent, high speed reactivity and long term, ambient storage and shelf life.
Accordingly, there is now provided polymerizable systems able to provide on-demand, high speed, 100% or near 100% solids, low catalyst requiring, entirely or substantially energy free curing, ambient curing, optionally crosslinking polymerizable systems that may be by design environmentally, biologically and/or metabolically compatible to meet clear and heretofore unmet needs.